Clinical trial enrollment, patient characteristics, and survival differences in prospectively registered metastatic colorectal cancer patients

Abstract

Background: Trial accrual patterns were examined to determine whether metastatic colorectal cancer (mCRC) patients enrolled in trials are representative of a general cancer population concerning patient characteristics and survival.

Methods: A total of 760 mCRC patients referred for their first oncological consideration at 3 hospitals in Scandinavia covering defined populations were registered consecutively during 2003 to 2006. Clinical trial enrollment, patient characteristics, and treatment were recorded prospectively, and the follow-up was complete.

Results: Palliative chemotherapy was initiated in 61% of the patients. Approximately one-third (36%) of patients receiving chemotherapy were included in a trial. The main reason for nonparticipation was failed eligibility criteria (69%). The median survival after chemotherapy was 15.8 months for all patients, and 18 months after combination chemotherapy. Trial patients had better prognostic characteristics and significantly longer survival than nontrial patients: 21.3 months versus 15.2 months when receiving combination chemotherapy. Poor performance status was the main reason for giving best supportive care only, and the median survival was then only 2.1 months. The median survival for all 760 nonresectable mCRC patients was 10.7 months.

Conclusions: mCRC patients enrolled into clinical trials differ in characteristics from patients receiving chemotherapy outside protocol and have better survival, even when given the same treatment. Although trial patients have a median survival close to 2 years, survival is lower for all patients receiving chemotherapy and much lower for all patients diagnosed with mCRC. Studies that better accept the heterogeneity of the population with mCRC are needed.